Context: October 24 is observed as World Polio Day every year in order to call on countries to stay vigilant in their fight against the disease.
Key Points

• It was established by Rotary International over a decade ago to commemorate the birth of Jonas Salk, who led the first team to develop the vaccine against the disease.
• 2020 theme for World Polio Day is “A win against polio is a win for global health.” 

Current Scenario

• According to the World Health Organisation, polio cases have decreased by over 99% since 1988, from an estimated 350,000 cases to 22 reported cases in 2017.  This drastic reduction is the result of the global effort to eradicate the disease. 
• In 2019, polio outbreaks were recorded in the Philippines, Malaysia, Ghana, Myanmar, China, Cameroon, Indonesia and Iran, which were mostly vaccine-derived (a rare strain of the virus genetically mutated from the strain in the vaccine. 
• According to the WHO, if the oral vaccine-virus is excreted and allowed to circulate in an un- or under-immunised population for at least 12 months, it can mutate to cause infections).
• As per the CDC, Afghanistan and Pakistan are the two countries that are the last stronghold of the wild poliovirus. In Pakistan, the number of reported wild poliovirus cases has increased in 2020.
• In 2020, only three countries in the world have reported the transmission of polio, which are Pakistan, Afghanistan and Nigeria.

Key Trends
Importance of this day

• It honours the contributions of those on the frontlines in the fight to eradicate the polio virus from every corner of the globe.
• The day also encourages a widespread use of safe and effective vaccines to curb the poliomyelitis, commonly known as polio. It is expected to become the second human disease ever to be eradicated after smallpox.

India’s situation with regard to Polio

• India was declared polio-free in January 2014, after three years of zero cases, an achievement widely believed to have been spurred by the successful pulse polio campaign in which all children were administered polio drops. 
• The last case due to wild poliovirus in the country was detected on January 13, 2011.

About Polio

• According to the US Centers for Disease Control and Prevention (CDC), “Polio is a crippling and potentially deadly disease that affects the nervous system.
• Because the virus lives in the faeces (poop) of an infected person, people infected with the disease can spread it to others when they do not wash their hands well after defecating (pooping). 
• People can also be infected if they drink water or eat food contaminated with infected feces.
• Most people with polio do not feel sick. Some people have only minor symptoms, such as fever, tiredness, nausea, headache, nasal congestion, sore throat, cough, stiffness in the neck and back, and pain in the arms and legs. 
• In rare cases, polio infection causes permanent loss of muscle function (paralysis). Polio can be fatal if the muscles used for breathing are paralyzed or if there is an infection of the brain.”
• The virus multiplies in the intestine, from where it can invade the nervous system and can cause paralysis. 
• Once that happens, the patient is crippled for life because there is no treatment for the affliction. Polio infection, however, can be easily prevented by a vaccine.
• There are three variants of the poliovirus, numbered 1 to 3. For a country to be declared polio-free, the wild transmission of all three kinds has to be stopped. 
• For eradication, cases of both wild and vaccine-derived polio infection have to be reduced to zero.

Causes of Polio

• Polio is caused by an RNA virus, where 85% of the infections are paralytic. 
• Poliovirus is most commonly spread in the areas where there is poor sanitation. 
• The virus can be spread through contaminated food and water. 
• Individuals infected with the poliovirus can spread the infection from their feces. 
• Also, direct contact with the poliovirus-infected person can cause poliomyelitis.

Polio prevention & treatment
There are two types of vaccine that can prevent polio:

• Inactivated poliovirus vaccine (IPV) given as an injection in the leg or arm, depending on the patient’s age. Only IPV has been used in the United States since 2000.
• Oral poliovirus vaccine (OPV) is still used throughout much of the world.
• The Polio vaccine protects children by preparing their bodies to fight the poliovirus.